Wholesale charges for retailers

The following information is a guide to wholesale charges levied on retailers. It does not relate to charges applied to trade effluent consent holders.

Primary trade effluent charges to retailers will be
calculated using one of three methods, as described below.

1 . Measured strengths

Every month, average sample strengths will be calculated per
trader and loaded to the Open Water market (CMOS) for inclusion in Mogden-based
charging calculations. Results will be backdated to the beginning of the month.
It is a retailer’s responsibility to provide flow data where required.

We will use analysis results from the most recent 10 samples
taken specifically to generate charging strength data (typically 24hr
composites).

A modified Z-test will be applied to each set of 10 results
to identify and eliminate outliers (both highs and lows).

The remaining results will be averaged to produce charging
strengths for suspended solids (@pH7) and chemical oxygen demand (settled
@pH7).

We will set the sampling programme to ensure that any set of
10 charging samples falls within a suitable period.

2. Fixed strengths

For processes that are standard across the country, fixed
strengths may be applied. In these cases, regular sampling will not be used to
generate sample strengths.

For example, most vehicle washes are currently billed using
fixed strengths for suspended solids and chemical oxygen demand. These are
adjusted from time to time to take account of new information, changes in
processes or new technologies.

These are similar to fixed strengths but are usually
calculated using an initial set of sampling data for a single trader. They can
be reviewed and amended at intervals as necessary and agreed between us and
retailers.

They are designed for lower risk, non-standard trade processes that
produce effluent of a predictable quality.

Application fees

There is a standard application fee of £446 across all
consented discharges.